1. Technical Field:
The present invention relates broadly to an air conditioning system to enable technical research and processing of materials under very strict humidity and temperature control parameters.
2. The Prior Art:
U.S. Pat. No. 2,545,491 discloses an air conditioning system for precisely controlling the temperature and humidity of air. The patented system essentially is a dual temperature generator which, in one mode, maintains a water spray temperature very close to the dewpoint, which acts as a humidifier or dehumidifier depending on the vapor pressure of the air presented to the spray and, in the second mode, controls the dry-bulb temperature of a chamber or room by reheating the air from the spray, as required.
One drawback of the patented system is the consumption of substantial amounts of energy in the form of reheat power.
Another drawback of the patented system is its inability to smoothly modulate the refrigeration capacity of the system over a sufficiently wide range.
Still another drawback of the prior art system is its inability to automatically change the water spray temperature set point in minute increments in response to demands for precise relative humidity control under experimental laboratory conditions.
It is the general objective of the present invention to eliminate the above drawbacks of the prior art by providing a precision relative humidity control means operating in sequence with air conditioning equipment to effect an extremely stable relative humidity control.
More particularly, in the present invention, the system possesses the ability to automatically change the water spray temperature set point in increments of 0.1.degree. C. responsive to demands for relative humidity control.
The present invention embodies a unique air temperature control system requiring as little as 1/10th the reheat power of the prior art dual temperature generator.
The invention further includes a precision refrigeration control system which allows smooth modulation of refrigeration capacity in the system over a range of 0-100%, in response to a water temperature controller, effecting a .+-.0.1.degree. C. temperature control at a spray header. Heretofore, large research laboratory areas (over 400 square feet) have been very difficult to control within close relative humidity tolerances. By means of the present invention, single point relative humidity constancies to .+-.1.0%, as well as control air temperature constancies to .+-.0.4.degree. C. in areas up to 3000 square feet, are routinely attainable.
Other objects and advantages of the invention will become apparent to those skilled in the art during the course of the following description.